


Collaboration

by SoloShikigami



Category: Undertale (Video Game)
Genre: Foursome - M/M/M/M, Incest, Multi
Language: English
Status: Completed
Published: 2019-04-07
Updated: 2019-04-07
Packaged: 2020-01-06 00:13:46
Rating: Explicit
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 1
Words: 2,771
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/18376970
Author URL: https://archiveofourown.org/users/SoloShikigami/pseuds/SoloShikigami
Summary: Sans never liked to get between anything or anyone, but he finds himself (pleasantly) overwhelmed when Papyrus, Edge, and Red put him in the middle.





	Collaboration

**Author's Note:**

> This was a collaborative piece between Muskka and I. Mus did a wonderful drawing, but due to it's NSFW nature, I'm refraining from providing a link at this time.

            The last place Sans ever thought he would be was standing between his brother and his brother’s copy from another world as they debated who would top if they had sex with each other.

            Sans and Papyrus had always wanted more than a fraternal bond, and only began consummating it recently with the arrival of the brothers from Underfell. It was obvious from the start that their “edgier” counterparts had been in a long-established relationship. Red encouraged Sans to confess and Edge worked with Papyrus, and the two had never been happier in all of their lives. 

            Sans had been curious what sex with either Red or Edge would be like, but he was shocked when Papyrus was the first one to voice that same curiosity. He wasn’t sure how he felt about it, but at the moment, his attentions were more towards trying to keep the two from coming to blows (heh) over it.

            “It is obvious that, as the one with more experience, that I would top!” Edge argued.

            “I am far more gentle and loving!” Papyrus said.

            “Who says I can’t be?” Edge said with a smirk. “Besides, what if your partner likes it a little rougher than what you are willing to provide?”

            Papyrus visibly bristled. “I’m sure a skeleton as great as I could provide my partner with whatever they wanted!”

            “Come on, you guys, you both have your talents,” Sans said.

            “Are you doubting the Boss’ ability to please anyone?” Red asked gruffly, moving to stand between Sans and Edge.

            “Aw, come on, Red, not you, too,” Sans sighed.

            “You didn’t answer my question, sweetheart,” Red growled, moving closer. 

            While he and Sans were about the same size, Red still rolled his shoulders and straightened his spine to look as intimidating as he could.

            And it was working.

            When Red took a step forward, Sans stepped back, his hands coming up in a placating gesture. He started when he bumped against Papyrus, who put steadying hands on his shoulders.

            Sans looked up to see Papyrus looking down at him, but the look on his face was unreadable.

            “You know,” Red murmured, pressing against Sans’ front with a smirk. “You’re kinda cute when you look scared.”

            Sans swallowed, eyes darting between Papyrus above him and Red in front of him, then he began to tremble as Edge loomed over them with a smirk firmly in place.

            “Uhm, guys?” Sans stammered, still looking between them all.

            “I think we may have found a way to compromise,” Edge purred, reaching over Red’s shoulder to caress the side of Sans’ face.

            The small skeleton flinched a little, suddenly becoming hyper-aware of where Red’s and Papyrus’ bodies made contact with his. Red was now looking at Sans as if he were a meal to be devoured, and Papyrus began to rub his shoulders as he bent to nuzzle the other side of his face.

            “This could be fun, Sans,” Papyrus murmured. “After all, you were curious about the abilities of our doubles.”

            “Were ya now?” Red asked.

            “Uh, well, uhm, you see, I-!”

            Red leaned in much too close. Fear flashed through Sans’ mind and body, but then the odd warmth that followed had him questioning his sanity.

            Was he getting turned on by his own fear?

            “Do not worry, brother, I am here, and of course, we could stop,” Papyrus said. “Though, I really want to do this.”

            Sans shivered as Papyrus bent more to lick his neck. His eyes darted between Red, who was still gazing at him hungrily, and Edge, whose intense stare was turning his bones into jelly.

            “We’ll make ya feel real good, sweetheart,” Red murmured, raising his hands to grip the lapels of Sans’ jacket.

            “Do we have your permission?” Edge asked, tipping Sans’ chin up a little.

            Sans’ lower jaw quivered as he whispered his consent.

            As soon as the words slipped past his mouth, Edge gripped Sans’ jaw firmly, tilting his head to expose more vertebrae for Papyrus to ravage. Red immediately pushed his hands under Sans’ white t-shirt to stroke his ribcage and spine. Edge leaned in and Sans expected a deep, rough kiss from the domineering skeleton.

            He was surprised, however, when Edge gently licked at his teeth, wordlessly asking for entrance, and only when Sans moaned did he move forward. He was slow, gentle, and very thorough, mapping out the inside of Sans’ mouth, touching on sensitive points that Sans didn’t know existed.

            Papyrus hummed, switching the licking to gentle nibbles, while Red’s hands wandered further down, his head pushed a little under Sans’ shirt so he could lick and nip at his floating ribs. 

            One of Sans’s hands gripped the shoulder of Red’s jacket, the other curling up and around Papyrus’ head, squirming a little between the three, off-balance and unsure of what to do.

            “Mmm, are we too much for you already?” Edge asked as he pulled away.

            Sans let out a small whine, his eyes flashing with protest as his arms moved to push the other two away; a weak attempt at regaining some semblance of control.

            However, Papyrus easily caught both arms and pulled them back, restraining the small skeleton.

            “I think we just may be,” Papyrus said, his voice dropping to a timbre that made Sans’ soul stutter and his knees go weak.

            “I gotcha sweetheart,” Red said, wrapping an arm behind him to keep Sans steady as he used the other to pull down his shorts.

            Edge smirked, knowing Red would take care of Sans and he walked around to Papyrus, stealing a kiss from him.

            “I almost hate to admit it, but you do look awfully sexy when you take control,” Edge murmured.

            “Nyeh, heh, heh, the Great Papyrus has many talents,” he replied.

            “Indeed. Going to be exciting to see what you can do.”

            Edge kissed Papyrus again, his hands wandering over his body, teasing and exploring.

            Red’s head was spinning, he could smell Sans’ magic and arousal and it created a light but heady potpourri as it mixed with the scents from the others. Slowly revealing Sans’ lower half as he pushed down the worn black shorts thrilled Red, his mouth beginning to water at the prospect of tasting those bones. Pale blue magic buzzed across pure white in swirls as it tried to find form, and Red leaned forward to lick along the crest of his pelvis, more than happy to help his magic along.

            Sans panted, his body going slightly limp between Papyrus and Red, part of him wanting to fight this; it was too indulgent, too good for him, wasn’t being involved intimately with his own brother bad enough?

            Red seemed to sense what was going through Sans’ mind, and while his hands stayed between his legs, touching, caressing, his fingers swirling in his magic, he stood back up to kiss him deeply.

            “It’s okay,” Red whispered. “We love you, Sans, it’s okay.”

            “B-but,” Sans began to stammer.

            “Shh, shh,” Red shushed him with a gentle finger over his mouth. “We’ve been through enough bullshit. _You’ve_ been through enough bullshit. You deserve love and care, now shut the hell up and enjoy this.”

            Before Sans could protest further, Red slipped a hand behind his skull and brought him in for a rough kiss while his other hand rubbed at his pelvis.

            It didn’t take much longer for Sans’ magic to manifest into two entrances; Red gently slipped his fingers through the folds of one while Papyrus pulled Sans back as he rubbed the growing bulge in his shorts against his backside.

            The resulting moan from Sans was almost too much.

            “Fuck, you sound beautiful,” Red murmured. “I want to be inside you so badly.”

            “W-wh-what are y-you wait-waiting for?” Sans panted.

            The three exchanged a look. Red smirked, pushing his shorts off, then dropping to his knees again, gripping Sans’ ass and leaning forward to lick at his pussy.

            “Stars, Red, please don’t tease,” Sans moaned, wriggling a little in the firm grip Papyrus still had him in.

            “Mmm, you taste good, sweetheart,” Red purred. “You’re getting pretty wet down here. You want my cock badly, dontcha?”

            Sans whined. Red laughed and lay back on the floor, stroking himself to full hardness. Edge moved back to Sans’ front to help Papyrus lower him into Red. The two tall skeletons held Sans just above Red for a moment, giving gim time to rub the head of his cock along the opening, wetting it and drawing more squirms and wanton moans from Sans.

            “Please, please,” Sans begged.

            “I think that’s enough,” Papyrus said.

            “Agreed,” Edge said with a nod.

            Sans expected them to lower him slowly, so he was shocked when they all but dropped him onto Red, his girthy cock stretching him, his head fell back and his jaw dropped, tongue slipping out the side of his mouth.

            “Stars, so big,” Sans moaned.

            “He’s adequate,” Edge murmured, reaching down to rub at the sensitive nub of magic above where Sans and Red were joined.

            “Fuck you, Boss,” Red snarled.

            “Mm, I do not think so, no,” Edge said casually. “Papyrus, I believe Sans needs a bit of a distraction.”

            “I believe you are correct, Edge, though he’s a pretty stubborn set of bones, we need to make the distraction good,” Papyrus said, considering their positions. “I know something that I can do, but, Sans will fall if I let him go.”

            Sans squirmed and whimpered.

            “C’mon, you guys,” he whined.

            Red groaned and rolled his hip up into Sans, making him cry out.

            “You know, despite his horrendous puns, Sans has a very talented mouth, Edge,” Papyrus said matter-of-factly.

            “Nyeh, heh, heh, you’re finally speaking my language,” Edge chuckled, standing up and unbuckling his pants.

            “Now, Sans, you’ll be a good boy for me now and show Edge what you can do, hmm?” Papyrus murmured.

            Sans shivered, his eyes focusing on Edge as he slid the leather belt from his pants and let them drop to the floor. He moved so he stood just over Red’s head and he bent forward a little to grip Sans’ arms. Papyrus let Sans go, and he almost immediately fell forward. Edge helped guide Sans’ hands to his hipbones, where he gripped them to steady himself.

            Of course, this put Sans face to face with Edge’s dick. He glanced up at Edge, who was smirking down at him. Red rolled his hips again, and he could feel Papyrus’ cool fingers brushing at his back entrance.

            “Come on, now, I believe Papyrus gave you an order,” Edge reminded him.

            Without another moment’s hesitation, and because of a sudden flare of defiance, Sans took all of Edge into his mouth in one smooth slide of tongue and teeth, forming a throat to swallow around him.

            “Guh! Shit!” Edge gasped, gripping Sans’ hands. “Oooh, you are good.”

            “Nyeh, heh, heh, told you so,” Papyrus murmured, kneeling down and dragging his long tongue across Sans’ other entrance.

            “Ooo, he likes that,” Red chuckled, continuing to roll his hips up, fucking Sans slowly and steadily. “He’s grippin’ me real tight now.”

            Sans moaned his appreciation, the vibrations traveling along Edge’ cock and making it twitch in his mouth. Sans felt a welling of pride for making the usually stoic and angry skeleton feel pleasure, but he nearly choked when something wet and slippery prodded him from behind.

            “Don’t stop, Sans,” Papyrus murmured against his flesh, nipped at his round bottom. “You cannot always be lazy, after all.”

            Sans whimpered and continue his task, switching between sucking Edge down and licking along his shaft as if it were a Nice Cream.

            “Damn, sweetheart, you feel so good,” Red murmured appreciatively.

            “Hold still for a moment, Red,” Papyrus said.

            “Huh? Why?”

            “Because it’s going to feel even better in a moment.”

            Red grinned up at Sans. “Better hold on, Sansy.”

            Sans should have figured it was coming (heh), but it still made him pull of Edge with a gasp, gripping the hipbones tightly as Papyrus slowly penetrated him from behind.

            “Oooooohhhhh, fuuuuuck,” Red groaned, falling back on the floor. “Shit, I can feel you through him.”

            “Mmm, yes, I can feel you, too,” Papyrus nipped the back of Sans’ neck. “You’re taking us both so well, brother, I am so proud of you.”

            Tears welled up in Sans’ eye sockets; the sensations were overwhelming, he was so full! Or, at least he thought he was, until Edge coaxed him to take his cock into his mouth again.

            _This is impossible,_ Sans thought to himself, the tears freely flowing down his face as he took all three of them. He felt like he was going to break, but the gentle caress over his skull from Edge, the gentle slide of Red’s hands down his ribs, and Papyrus’ thumbs rubbing soothing circles into his hips, he knew he was fine, being well cared for, and he wanted to show his appreciation.

            Papyrus and Red set up a rhythm, gently moving in and out of Sans in tandem. Sans continued alternating between licking and sucking on Edge, feeling a thrill every time he felt either of them twitch or heard either of them moan. They were all there, all part of one another, and Sans was the one who brought them all together, and that was a feeling he decided that he could get used to.

            “Fuck, Boss, can’t take anymore,” Red grunted.

            “Nyeh, I’m pretty close, too,” Papyrus panted. “I can’t wait to fill you up, Sans.”

            “Please, do it, please,” Sans begged.

            “Mmm, all right, then,” Edge said, gripping Sans’ skull and starting to thrust into his mouth.

            The others took it as a sign to speed up their paces. Red’s hips stuttered first, and he growled as he came, thrusting deep, releasing red magic into blue.

            Sans moaned, his body twitching as it also peaked.

            “Fuck, Sans!” Edge howled. He had been trying to hold out, but Sans’ orgasmic moan reverberating on his cock made him lose his control and released into Sans’ waiting throat.

            Sans lost his grip on Edge’s hips and collapsed on top of Red, who wrapped his arms around Sans, holding him for Papyrus, who was still thrusting hard and deep.

            “You okay, Boss?” Red asked as Edge fell to his knees next to them.

            “Yes,” Edge said with a slight grumble, annoyed that his control was wrenched away so easily. With a smirk, he reached under Sans, his fingers seeking out that now overly-sensitive nub of magic and stroking it roughly.

            Sans cried out, his body shaking from over-stimulation, building up to another peak quickly.

            “Oh, yes, brother, yes, Sans, cum for me,” Papyrus murmured.

            Sans screamed as his second release crashed over him, and with a cry of his own, Papyrus also found his completion, wrapping his arms around Sans as he, too, collapsed on the floor with the others.

            They all were silent, catching their breaths, Sans’ body was shaking through the aftershocks if his orgasm, making small whimpers every time he went to move.

            “You okay, sweetheart?” Red asked.

            “Sans?” Papyrus asked, voice filled with concern.

            “Speak to us,” Edge prompted.

            “’m okay, I’m okay,” Sans insisted in a slightly shaken voice. “That, just, it was…”

            Red chuckled. “You said it, pal.”

            “But which of us made the better Dominant?” Papyrus asked. “This really didn’t solve it, did it?”

            “You all are _tops_ in my book,” Sans murmured.

            Papyrus and Edge both glowered while Red chuckled.

            “We can fuck you into oblivion you know,” Edge warned.

            “Edge! Language,” Papyrus chastised, his face turning orange.

            “Hey, give me some ketchup and a nap and I’ll gladly let you guys try again,” Sans murmured sleepily, nuzzling into Red.

            “I’m with him,” Red murmured.

            Edge rolled his eyes. “All right, fine. Let’s at least get cleaned up before you two lazy shits fall asleep.”

            Once they all bathed, Papyrus and Edge tucked Red and Sans into bed, the two snuggling with each other as the other two headed back down to begin preparing dinner.

            “You know,” Edge murmured, coming up behind Papyrus and wrapping his arms around his waist. “If you’re up for it, those lazybones will be asleep for a while. Maybe we can do some training of our own.”

            “Nyeh, heh, heh, are you certain it will be me learning the lesson?” Papyrus said with a cheeky smirk.

            Edge met that smirk. “Is that a yes, then?”

            Papyrus turned in Edge’s arms, throwing his around his neck and kissing him deeply.

            “Does that answer your question?” Papyrus murmured.

            “Naughty boy,” Edge replied.


End file.
